Pipe elevator



A. L. STONE PIPE ELEVATOR Dgc. s, 1953 3Sheets-Sheet 1 Filed Oct. 25, 1948 FIG. 4A.

FIG. 5. lNVl;ENTOR ATTOR NEY.

Dec. 8, 1953 A. L. STONE 2,561,979

PIPE ELEVATOR Filed Oct. 25, 1948 3 Sheets$heet 2 so so 28 u I BY A 24 25 2. lb 14 A T RNQ.

Dec. 8, 1953 A. s'roNE 2,661,979

PIPE ELEVATOR Filed 001;. 25, 1948 s Sheets-Sheet 5 I FIG. 6

I v INVENTOR.

e FIG. u.

Patented Dec. 8, 1953 UNITED STATE OFFIE 2,661,979 Prrn ELEVATOR ration of Delaware Application October 25, 1948, Serial No. 56,402

8 Claims.

This application is a continuation-in-part of my co-pending applications Serial No. 727,712, filed February 10, 1947, entitled Elevator for Pipe, now U. S. Patent 2,496,360, and Serial No. 745,367, filed May 2, 1947, entitled Combination Hook and Elevator, now abandoned.

The present invention is directed to a pipe elevator.

More particularly, the present invention is directed to a device adapted for handling vertical sections of pipe in the drilling of boreholes.

When moving a vertical or substantially vertical tubular structural member from one position to another, it may be desirable or necessary to provide means for engaging with the tubular member for suspending it during the operation. An example of such an operation is the handling of sections of drill pipe in a derrick during the operation of drilling a borehole. In such an operation a derrick is mounted over the borehole and is arranged for suspending the drill. stem or sections of pipe used to make up the drill stem. The conventional hoisting mechanism employed includes a crown block, a drilling line having one end secured to a hoisting drum and suspending a traveling block from the crown block, a hook carried by the traveling block and an elevator suspended from the hook for engaging and disengaging with the end of sections of drill pipe.

Heretofore it has been conventional to arrange the elevator so that it engages with an external shoulder. Accordingly, it has been usual practice to form a shoulder on the tool joint used in making up the drilling stem for engaging with the elevator but under some circumstances where socalled external flush joint drill pipe has been used. a plug has been provided for defining a shoulder capable of engaging with the elevators heretofore employed.

Conventional elevators arranged to engage with an external shoulder at the upper end of the length of pipe to be handled ofier disadvantages well known to the art. These elevators must be manually engaged with and disengaged from the pipe being handled.

vator presents difficulties. In the interest of economy as well as good structural design, it is not desirable to provide tool joints with external shoulders. Elevator plugs are unsatisfactory be duces an additional hazard inasmuch as it is sometimes desirable to rotate the pipe while sus- In addition, the provision of an external shoulder to engage with the ele pended from the elevators and the elevator plug may come loose during the rotational operation. The hook assembly conventionally employed by drilling rigs serves several functions. This assembly includes a swivel bearing. In addition to suspending the elevators, in one design the hook portion is arranged for supporting the bail of the drilling swivel and when so used the hook carries the load of the swivel and the complete drill string and in addition the unused elevator. At the time the rotary swivel is used for drilling, the swivel bearing in the hook is locked against rotation. A variation of this arrangement is an assembly wherein the elevator is adapted to engage a member mounted on the swivel bail, this member duplicating the shape of a short section of drill pipe with a. tool joint shoulder so that the hook assembly actually has no hook shaped member; i

- It is anobjeot of the present invention to provide a pipe elevator which may be engaged with and disengaged from the thread end of a section of pipe withoutmanual assistance. It is. another object of the present invention to provide an expandable chuck adapted for engaging with athreaded object with an indexing means to insure that the threads of the chuck are in proper relationship. with the thread with thread end of a section of pipe with an indexing means so that the thread engaging portion of the elevator is always in correct position when errgaging with the threads of the pipe.

Itis another object of the present invention to provide an assembly capable of performing the functions now performed between a conventional hook assembly and elevator assembly in a drilling rig.

More specifically, it is an object of the present invention to provide a structure which will releasably engage with the threaded portion of a section of pipe, which will support the pipe with its axis vertical to allow rotation of the pipe with reference to the suspensionpoint of said structure and which will incorporate spring means adapted to raise a stand of the drill pipe av short distance so that the threaded end of a stand when disconnected from the remainder of the drill string is jumped up to clear the upper threaded end of the remainder of the pipe. Further, it is an object of the present invention to provide an indexing means, that is, so that the threads of the engaging device fit properly with the threads of the pipe upon engaging the elevator.

Other objects and advantages of the present invention may be seen from the following description taken in conjunction with the drawing in which Fig. l is an elevation, partly in section, showing an embodiment of the present invention as it appears suspended from the travelling block i and supporting a section of pipe;

Fig. 2 is a fragmentary view, partly .in section, of the device of Fig. 1 with the parts shown in the position they occupy when the device is suspended from the traveling block and is not supporting a load and with'the pipe-engaging parts in their retracted or disengaged position;

Fig. 3 is a fragmentary view, partly in section, of the device of Fig. 1 with the parts shown in the position they would occupy after the previously suspended device'has been'lowered to engage with a box end of a section of pipe so that the pipe engaging parts are in their expanded or engaged position and the device is supported by the engaged pipe;

Fig. 4 is-a fragmentary view showing details of construction of partswhich are in the same relative position as in Fig. 2 when the pipe engaging portion is in its retracted or its engaged position;

Fig. 4a is a view of a member of the assembly of Fig. 4;

Fig. 5 is a view showing details of construction of the same parts as shown in Fig. ,4. but with-the parts in the same relative position as shown in Fig. 3 when the pipe engaging parts are in their engaged or expanded position;

Fig. 6 is an elevation, partly in section, of the pipe engaging portion or chuck of the embodiment of the foregoing figures;

Fig. '7 is a view taken along line VII-VII of between the indexing means of the embodiment of the foregoi g preceding vfigures and the box of .a tool joint with ,a portion of the tool joint cut away to show the upper end of ,i'tsthread;

Fig. 13 is a view similar to Fig. 12 but with the indexing means and the tool joint thread in a different angular relationship;

Fig. 14 is a view looking upwardly in the indexing means shown .in Figs. 12 and 13;

Fig. 15 is a view looking down at the tool joint box of Figs. 12 and 13;

Fig. 16 is a fragmentary view showing another embodiment of members which may be substituted for the embodiment shown in Figs. 2 to 5, with the parts in the relative positions occupied rotation between the engaged member and the point at which the assembly is suspended. Further, the device may be releasably locked to prevent such rotation. In addition, the device embodies means ior jumping a suspended stand of pipe a short vertical distance after it had been disconnected from another section of pipe where by the pin end of the disconnected stand is drawn upwardly to clear the box at the end of the section from which it is disconnected.

Forconvenience the device shown in the drawing has its principal parts or assemblies designated by letters and the parts of a principal part or the component parts of anassembly designated by numerals.

The embodiment of Figs. 1 to 15, inclusive, includes as principal parts or assemblies chuck assembly A, mandrel B, piston assembly C, body D, power spring E, mandrel locking assembly F, housing G, compression spring H, bearing assembly I, .housing lock J, releasing assembly K and signal assembly L.

The embodiment shown in Figs. 16 and 17 includes as principal partsga mandrel B and Ina-ndrellocking assembly F. It is to be understood that these parts may be substituted for the corresponding parts '3 and G shown in detail in Figs.2 to 5, inclusive.

in both the embodiments shown in the drawing, the chuck has jaws adapted to assume an expanded state for engaging with threads (as the threads of a-tool joint on the end of a section of drill pipe) and a contracted state for disengagement from the threads. Au indexing assembly cooperates with the jaws of the chuck assembly to insure that when the jaws expand into the pipe the threads defined by the jaws will properly engage with'the threads of the pipe, that is, so that the crest of the thread defined by the jaws coincides with the valleys of the thread of the pipe. Mandrel B is arranged to assume an'upper position which allows the chuck assembly to contract and a lower position which its lower position.

Piston C fits slidably in body assembly D and connects-with mandrel B. Upward movement of piston C forces mandrel B upwardly and allows the chuck assembly A to assume its contracted state. Mandrel locking assembly F is adapted to lock the mandrel B either in its upper or lower position. Power springs F bias the piston C downwardly and this in turn exerts a bias on the mandrel B tending to force it to its lower position. Housing G is adapted to be supported from the traveling block and spring H is a compression spring arranged to transmit the load from body D to housing G. Releasing assembly K is arranged for introducing compressed air within the assembly so that pressure is exerted against piston C to bias mandrel B to its first or upper position. Signal assembly L provides a means for indicating when the device is properly engaged with a section of pipe. Bearing assembly I allows relative rotation between body D and housing G while releasable lock J is arranged for locking body D against relative rotation with respect to housing G.

lhe construction of the device of the present invention will now be described in detail.

The embodiment of Figs. 1 to 15 will first be described. Chuck assembly A'consists of a compress on ring is, a plurality of jaws II, sleeve I2, indexing ring is and guide cone l4. Sleeve I2 is slidaoly arranged in the lower portion of body D and when it is in its lower position it is sup: ported by inwardly extending circumferential shoulder Id of body D. Sleeve 52 definesa circular groove I? for receiving shoulders I8 of jaws II. The outer surface of sleeve I2 is provided with a longitudinally extending slot to receive key ii and to prevent rotation between body D and the sleeve. A radially extending screw 9 extends from the sleeve into a corresponding radial passage in a jaw I i to prevent rotation between the jaws and the sleeve. In other words, the chuck assembly may move longitudinally but not rotatably with respect to body D.

Indexing ring I3 is split with the two halves secured together by cap screws I9 so that indexing ring It is n effect a member of constant diameter. Each jaw member Ii defines a radially extend ng passage 28 and screws 2! mounted on indexing ring I3 extend slidably into each of said radial passages 2!]. Guide cone I 4 defines radially extending slots 22. It is made up of two l ke parts held together by cap screw 23. The mode for securing the jaws to sleeve I2, indexing ring is and cone Hi allows the entire chuck assembly to move longitudinally with respect to body D and also allows jaw members I I to move radially. The sleeve, indexing ring and guide cone are concentri c and remain fixed in position with respect to each other at all times. Jaws I I move radially but remain concentric with respect to the axis of chuck assembly A. Compression ring I!) biases the jaws radially inwardly to a contracted or disengaged position.

The jaw members i! of chuck assembly A cooperate so that the outer surfaces thereof define a substantially complete screw thread 2 3 with the only incomplete portion of the thread being the space which separates the jaw sections. The inner surfaces of the jaw members define a passage 25 for receiving mandrel B. In the embodiment shown in the drawing, the lower portion of the mandrel is square in section and, accordingly, passage 2% is square in configuration. To prevent dirt and foreign particles from entering passage 25 the spaces between the sides of the adjacent jaw members II are sealed by rubber packing members 25 and the space between guide cone Hi and jaw members i I is packed off by packing ring 2?.

In the embodiments shown in the drawing, the elevator is adapted to engage with the tapered thread such as may be employed for the tool joint of drill pipe. The lower surface of indexing ring is defines an indexing surface 28 which in the shape of the lower surface of a thread extending through an arc of approximately 360. The indexing surface must extend through approximately this length of arc although satisfactory operation may be obtained if it is a few degrees less,-say 355". If desired, the thread could extend through a greater length than 360 but the usable portion for indexing is limited to 360 and there is no advantage of extending it a greater distance. In order for this indexing means to operate properly the thread of the tool joint with which it is to engage should terminate as a true spiral. A tool joint thread of this character is shown in Figs. 12, 13 and 15. The operation of the indexing surface 28 in connection with a tool joint thread is illustrated in Figs. 12, 13, 14 and 15.

Fig. 14 is a view of the indexing surface 28 looking upwardly. In this view line 29 represents the vertically extending shoulder with which'spiral thread surface 28 terminates.

Fig. 12 is an elevation, partly in section, showing the index ring I3 immediately above tool joint 3%). Tool joint 38) defines a thread 3i which terminates as a true spiral and ends in shoulder 32. This figure illustrates the relationship the indexing ring and the tool joint may assume when the elevator assembly is being lowered to engage the tool joint. In this figure shoulder 29 of the index ring overlaps by a few degrees shoulder 32 of the tool joint so that if the elevator is lowered the index ring will strike against the tool joint thread, thereupon the chuck assembly A will be held against further downward movement with the thread 24 defined by jaw II lined up properly with thread 3| of the tool joint and if the mandrel locking member F is activated by further lowering of body D the mandrel B will expand the jaw members I I into the tool joint thread.

Fig. 13 is similar to Fig. 12 but shows index ring I3 rotated a few degrees (in the counterclockwisedirection looking downwardly) with re-v spect to shoulder 32 of the tool joint thread so that shoulder 29 will pass shoulder 32 upon lowering'of the elevator assembly and indexing surface 28 will engage with thread 3i approximately one pitch below the point they will engage in Fig. 12. However, when the indexing ring [3 does engage with thread 32 of the tool joint the thread defined by jaws II will be lined up "position between the indexing member I3 and the tool joint thread 3 I.

"Mandrel B consists of a lower tapered square section 20, an upper section of generally cylindrical shape i I, an upper locking portion consisting of tapered surfaces 42 and 33, a lower locking portion consistingof tapered surfaces st and t5,

packingrings 46 and. an upper head 4'1.

,LI Piston C is'arranged to move mandrel B longitudinally but is connected therewith so as to produce an initial jar for releasing the mandrel after the chuck A has been used for supporting a load. Elston C defines a cavity '38 for receiving head 41 of mandrel B. Cavit s8 is defined by cylindricalwall 49 and end wall 59. A circular inwardly extending ledge 5| encircles body of the mandrel below head 47. Piston C defines an upwardly extending tube 52 which serves as a passage for compressed air. This passage discharges into radiallyextending passages 53 and thence intb longitudinally extending passages 5d which'discharge below piston C. The outer cy- 7 lind-ric'alsurface of piston C is. provided with packingiring'fili;

Body'D is of a somewhat-irregular shape but i generally tubular having an upper wall-portion 5E and having its upper end terminating in an outwardly extending shoulder 5'! and defining an inwardly extending wall 5% which is pierced by a central passage 53. A tube 69 extends downwardly from wall 58. The outer surface of wall 56- defines key Ways 56'. Below wall 561s an inwardly extending wall or shoulder 6! pierced by a central passage 52 and below wall St the body defines an inner cylindrical surface 63 having a key Way 5 for receiving key 8- and terminating in lower shoulder 55. The lower outer portion of body D-defines ears tfi-adaptedior supporting the links of a conventional type elevator (not shown on-the drawing), if desired.

Inwardly extending wall or shoulder 6| defines or has attached.- thereto a downwardly extending tube EB which has an upper portion of its Wall thicker than its lower portion to define shoulder 81 and is provided with longitudinally extending slots 58 in its thinner wall portion.

Itwill be seen that piston slides longitudinally within body D with packing ring 55 in contact with the inner surface of cylindrical portion 55. Mandrel B slides in the central passage 62 definedby wall i with packing rings it making a fluid-tight seal therewith, the chamber between pistonC and wall 6! being designated as as and is the chamber in which compressed air discharges after flowing through passages 52-, 53 and 5 1. Power spring E is arrangedwithin tube to with its upper end in contact with shoulder 51 and its lower end in contact with piston C so that it exerts a downward bias thereon. outwardly extending shoulder 5'? serves as a support for compression spring H.

Mandrel locking assembly F is arranged for releasably locking mandrel B in either an up position or a down position. When mandrel B is locked in its up position, chuck assembly A is movable and the mandrel B may be released by upward movement of chuck assembly A. When mandrel B is in its down position, it is locked to chuck assembly A and may be released by downward movement of body D with respect to the mandrel B and chuck assembly A.

Mandrel locking assembly F consists of a locking ring it, wedge member l! and spring 12. The upper end of locking ring is terminates in shoulder. is while its lower end terminates in an outwardly extending shoulder "i i, The locking ring defines a central passage having a lower cylindrical portion 75 and an upper tapered portion 16. Wedges 7i define locking surfaces '17 and 18 and an outer surface is. Wedge members' are arranged in longitudinally extending slots $8 in tube 66 or" body D and are encircled by locking ring ll] so that outer surfaces 19 are incontact with tapering surface 16 of the locking ring. Spring 12 biases locking ring 16 downwardly.

Where mandrel B is in its upper position, as shown in Figs. 2 and 4, it is locked against downward movement by contact of locking surface 11 with. tapered locking surface 44 of th mandrel. When the mandrel is raised'to. its upper position by compressed air entering chamber 69 and exertin pressure against the lower surface of piston C which in turn pulls mandrel B upwardly, if locking ring "ill is free to move under the influence of spring l2, spring i2 forces the locking ring downwardly so that tapered surface "it of the locking ring slides over surface 79 of 8 the Wedges forcing them inwardly until the looking; surface H is in contact with the tapered lockingsurface 44,- of the mandrel. Thislocks the mandrelinitsup position again the bias exerted on the mandrel by power spring E throughpiston assembly C after the compressed air is released from chamber 69.-

The mandrellocking assembly F releases the mandrel from its upper position when the lookingring it is moved upwardly with respect to body D. This relative movement of locking ring It occurs when the chuck assembly A is held against downwardmovementand body D moves downwardly. When the lower shoulder of lookingring; H3 comes incontact with the chuck assembly A, it is held against further movement while continued downward movement of body D, wedges 'I I- and. mandrel B allows the wedge members 'H- to move radially outwardly as well as downwardly with body D thereby releasing mandrel B so thatpower spring E can force it downwardly toits second position.

Maud-rel lockingassembly F is able to lock mandrelB in its lower position when body D has been lifted upwardly a sufficient distance to move locking ring H3 out of contact with chuck assembly A. When this occurs spring 12 exerts its force against locking ring ill in turn causing the tapered surface 16 of locking. ring F to force wedges it against the tapered locking surface 43 of mandrel B. This looks the mandrel in the down position; as illustrated. in Figs. 3 and 5. It is to. be noted that when the mandrel is locked in its upper position, it is locked against the bias exerted by the power spring E. But when it is locked in it down position, it is locked againstpossible. upward movement which might be produced by accidentally releasing compressed air. into chamber 69 while the mandrel is supporting a load.

When-mandrel locking assembly F has locked the mandrel in itslower position, as shown in Figs. 3 and 5, it may be released by holding chuck A against downward movement and allowing the weight ofbody D to be exerted through tube 86 against the upper ends of wedge members H thereby forcing locking ring Hi to move upwardly with respect to wedge members it while the wedge members simultaneously move radially outwardly until they have moved a suiiicient distance torelease mandrel B; after the weight of the body has been exerted on the upper ends of wedge members 1 l, air pressure may be admitted to chamber 69 to act againstthe lower surface of piston 0 thereby driving the pistonupwardly, compressing power spring E and forcing the mandrel B to its'upper'position. When the mandrel Breaches its upper position it may be locked by mandrel 10 forcing wedges H in contact with tapered locking surface 44 of the mandrel as heretofore explained.-

Housing G is adapted to be supported from the traveling block and for this purpose is provided with abail 83 at its upper end. The lower end of housing G defines a shoulder arranged to support bearing assembly I. The bearing assembly. consists of lower race 82, upper race 83, and bearings. 84. Supporting ring 85 slidingly embraces wall portioniifi of body 13.. The outer periphery of ring 85! defines. a plurality of locking grooves 86 for. cooperation with lock J. The inner surface of the ring is provided with longitudinally extending grooves for receiving keys 8'!- which fit slidingly in key ways 56 of body D to prevent angularv movement between body D 9, and housing G. Supporting ring 85 rest on bearing assembly I.

Suspension spring I-I encircles wall portion 56 of body D with its lower end resting on supporting ring 85. When the elevator is supported from ball 88, the load is transmitted from chuck assembly A to body assembly D and from shoulder of body D through spring l-I, ring 85 and bearing assembly I to shoulder 8| of housing G. Overtravel is provided so that housing C- is free to slide downwardly in the event that the downward movement of body I) is stopped when the device is being lowered. This provision of over-travel is particularly useful when engaging the device in that when the chuck assemblyA engages with a stand pipe the downward 'move-' ment of the chuck as well as body D must be abruptly terminated but the housing G- with'the heavy traveling block (not shown in the drawing) may move downward the distance of the overtravel giving the driller an opportunity to stop the blocks and housing G after he has engaged the elevator with the load.

Lock J is mounted on housing G and is adapted to engage with any one of locking grooves 85 of supporting ring 85. It will be understood that look J may be of a conventional type arranged to assume either an engaged position or released position by manipulation by the driller and, ac-

cordingly, the construction of lock J is not shown supply of compressed air so connected through air hose Q! provided with valve as to housing G by means of a suitable fitting 93. While a tank is shown in the drawing as a means for supplying compressed air, it will be understood that this is for illustrative purposes only and that conventional means such as a conventional air compressor provided with a reservoir may be employed for this purpose. Valve 92 is provided with an operating handle 9t shown in position a by solid lines and in position b by dashed lines. Valve 92 is provided with an exhaust vent Sill. Fitting as is connected to tube 96 which, for purposes of simplifying the drawing, is shown as a portion of housing G. Tube 95 is concentrio with tube 52 of piston assembly C and is provided at its lower end with packing 9? which makes a fiuidtight seal with the outer surface of tube 52.

When the valve handle as is in position a, compressed air supply $3 is in fluid communication with chamber 69 allowing air pressure to be exerted on the underside of piston assembly C. When the handle of the valve is in position b it prevents flow of compressed air from air supply at and simultaneously exhausts chamber 69 to the atmosphere through exhaust vent $5.

It will be understood that the releasing assembly K is for the purpose of supplying compressed air pressure to chamber 59 for forcing piston C and mandrel B upwardly to allow chuck assembly to assume its retracted position. Assuming operating handle 9% is in its b position and the elevator load has been lowered to rest, the chuck assembly A may be released and mandrel B moved from its lower to its upper position by allowing the weight of body D to rest on wedges "which in turn forces locking ring 1B upwardly and allows the wedges to move radially outward to release mandrel B. Thereupon the operator may move valve lever 94 from its 2) to its a position to apply air from air supply to chamber 69. This air pressure causes piston assembly 0 to move upwardly until it strikes head of mandrel B giving the mandrel a jar to loosen the squared portion lll from jaws I I and thereafter the continued application of air pressure against piston forces it and mandrel B upwardly against power spring E to its upper position. lvlandrel B is now. in its upposition and chuck A is retracted. The mandrel locking assembly F may then be allowed to operate and lock the mandrel in its upper position by raising body D until locking ring it is moved upwardly out of contact with chuck assembly A and assumes the position shown in-Figs. 2 and 4. The operator may then move valve handles! from it to 19 position thereby bleeding air from chamber 59 to the atmosphere and the mandrel B is locked in its upper position by wedge member ll. Y

The valve lever 94 preferably should remain n the b'p'os'ition all of resume the elevator is carryingits load. However, if the lever is accidentally moved to itsa position while the' chuck is" carrying a load, mandrel B is locked against upward movement y 'th'elocking means previously described so that the accidental manipulationof valv'e'leve'r'e i at this time will not cause the elevator to drop its load. s

' Guide funnel I05 i's-s'ecured to" the lower end of body D by cap screws'lllfi. ,Guidefunnel Hi5 aids in guiding the chuck assembly A into posi-' tion for engagingwith a'section of pipe.

k The signal assembly Lmay be any suit'ableisignalling device arranged to give a signal when the chuck A has assumed its expanded position. Forpurp'os'es of illustration, an assemblyis shown consisting of bell lfll," plunger [02 and striker arm Hi3. PlungerflllZ'fis slidably arranged in a passage defined by'shoulder 6|, of body D with itslower end belovvthe shoulder and its upper end abover thegshoulderf Aspring its biases plunger I02 in its upper position. When the de-. vice is engaged .with'a, section of pipe; piston C is forced downwardly by power spring'E and in turn drives'mandrel B downwardly. When the piston C has,been.moved downwardly, such a distance which forces chuck A to expand, for

proper engagement with a tool joint, it strikes the upper endof plunger Hi2 and forces it downwardly to rotate striker arm m3 and ring bell 10!. However,if for any reason the chuck assembly A doesnot index properly with the tool joint and the crest of the threads of jaws. H expand against the crest of the threads on the box, the mandrel B will not move to its lower position and, therefore, the piston assembly C will not move down a sufiicient distance to trip plunger Hi2. It is impossible for the operator to view chuck assembly A because it is wholly concealed by uide funnel I65 and'even if guide funnel 5535 were not present it would be partially concealed by the box of the tooljoint. However, if signal assembly L emits a signal the operator will lmow that the device has engaged properly with the threads of the jaws but if the signal assembly L fails to give out a signal the operator will know that the elevator has not engaged properly and that he must disengage the elevator from the load and make another attempt to stab.

Figs. 16 and 17 are fragmentary'views showing aeeneve another embodiment of locking means for locking the mandrel in position. In this embodiment the mandrel is designated as B and the mandrel locking assembly as F. Fig. 16 shows the mandrel locked in its upper position and Fig. 17- shows the mandrel locked in its lower position. In this embodiment of the present invention, body D defines a downwardly extending tube I66 which is provided with circular openings 168 for receiving locking balls I'll. Locking ring I defines a central passage having a lower cylindrical portion and an upper tapered portion I18. Mandrel B defines a lower portion I40 having a square section, a lower locking groove 1% and an upper locking groove I43. When mandrel B is in its upper position it may be locked by locking balls l'ii fitting into locking groove Hid, the locl ing balls being biased inwardly by contact wit tapered surface We of locking ring I10. Forcing locking ring no upwardly against the bias exerted by spring 72 allows locking balls ill to move radially outwardly thereby releasing mandrel B so that it may move downwardly. When mandrel B is in its lower position, as shown in Fig. 17, and locking ring H0 is forced into its downward position by spring 72, looking balls HI fit in looking groove I43 and are forced into this position by tapered surface N6 of locking ring H5 thereby locking mandrel B against upward movement. It will be understood that when using the embodiment of Figs. 16 and 17, the remainder of the apparatus may be identical with that described in conjunction with the preceding Figs. 1 to 15 and, accordingly, these parts will not be described again in detail.

From the foregoing description of the two embodiments, it will be seen that the elevator disclosed is adapted to be suspended from the travcling block and when lowered to stab a tool joint box the expanding chuck indexes automatically and engages automatically. The manipulation required is merely the closing of valve 92 after the chuck has been stabbed into the box preparatory to carrying a load and the opening of valve 92 after the load has been lowered to release the elevator from this load which releasing operation movesthe parts of the elevator into, stabbing position ready to be engaged with another load.

While I have disclosed specific embodiments of the present invention, it will be obvious to a Workman skilled inv the artthat various Changes may be made without departing from the scope of the invention and it is my intention to. em.-

brace such changes in the hereto appended 7 of the body including a plurality of jaw members mounted for radial movement outwardly from a retracted position to an extended position, the outer surfaces of said jaw members defining at least a portion of a screw thread adapted to mate with the screw thread of saidpipe, resilient means in contact with said jaw members for holding them in the retracted position, an indexing member carried by said jaw members for indexing the screw thread defined by said jaw, members with the screw thread of said pipe, a mandrel carried by the body which may assume an upper position to retract the jaw members radially inwardly and movable to a lower position to force jaw members radially outwardly and an assembly operatively connected to said mandrel for moving the mandrel from its upper position to its lower position or vice versa having a biasing means normally urging said assembly from an upper position to a lower position and having a fluid pressure means urging said assembly from a lower to an upper position.

2. A pipe elevator for engaging with and suspending a pipe having its end terminating in a spiral screw thread comprising, in combination, a body, a movable chuck assembly carried by the lower end of the body including a plurality of jaw members mounted for radial movement outwardly from a retracted position to an extended position, the outer surfaces of said jaw members defining at least a portion of a screw thread adapted to mate with the screw thread of said pipe, resilient means in contact with the jaw members for holding them in the retracted position, an indexing ring of fixed diameter defining a surface of an end of a thread of fixed diameter corresponding to an end of the thread defined by said pipe, a mandrel carried by the body which may assume an upper position to retract the jaw members radially inwardly and movable to a lower position to force said jaw members radially outwardly, an assembly operatively connected to said mandrel for moving the mandrel from its upper position to its lower position or vice versa having a spring normally urging said assembly from an upper position to a lower position and having a fluid pressure means urging said assembly from a lower to an upper position, and a mandrel locking means adapted to lock said mandrel in its upper position and actuated by movement of said chuck assembly for releasing the mandrel from its upper position to assume its lower position,

3. A device in accordance'with claim 2 in which a si nal assembly is cried by the body and said signal assembly is provided with a signal producing part arranged in operating relationship to the mandrel movingass inbly for contacting said signal producing p t with said mandrel moving assembly on engag merit of the screw thread of the jaw members with th screw thread of the pipe whereby the mandrel movin. assembly and the mandrel move to their lower position a sufficient distance for said mandrel movin assembly to contact said signal producing part and the signal assembly emits a signal when the jaw members engage the thread of the pipe.

l. A device in accordance with claim 6 in which a signal assembly is carried by the body and signal assembly is provided with a signal producing part arranged in ope ating relationship to the mandrel moving assemb J for contactin said signal producing part with said mandrel moving assembly on engagement of th screw thread of the jaw members with the screw thread of the pipe whereby the mandrel moving assembly and the mandrel move to their lower positions a sufiicient distance for said mandrel moving assembly to contact said signal producing part and the signal assembly emits a signal when the mandrel is moved to its lower position for the jaw members to engage the thread of the pipe.

5. A device in accordance with claim 2 in which said chuck assembly includesa guide cone carried by the jaw members arranged to remain concentrio with said indexing means.

6. A pipe elevator for engaging with and suspending a pipe having its end terminating in a spiral screw thread comprising, in combination, a housing adapted to be suspended from a traveling block, a bearing assembly carried by the housing, a. body assembly arranged to be supported from said bearing assembly, a releasable lock carried by the housing adapted to lock the body against rotation with respect to said housing, a longitudinally movable chuck assembly carried by the lower end of the body including a pluarlity of jaw members mounted for radial movement outwardly from a retracted position to an extended position, said jaw members defining at least a major portion of a spiral screw thread adapted to mate with the thread of said section of pipe when the jaw members are in their radially extended positions, resilient means in contact with the jaw members for holding them in the retracted position, an indexing member mounted on said jaw members and defining the surface of the end of a thread of fixed diameter extending through an arc of approximately 360 corresponding to the end of the thread of the pipe, a key securing the chuck assembly to the body to allow longitudinal movement while preventing angular movement, a mandrel carried by the body and adapted to assume an upper position to allow the jaw members of the chuck assembly to be retracted inwardly and movable to a lower position to force the jaw members radially outwardly, an assembly operatively connected to said mandrel for moving the mandrel from its upper position to its lower position or vice versa having a spring normally urging said assembly from an upper position and having a fluid pressure means urging said assembly from a lower to an upper position, and a mandrel locking assembly arranged to be activated by the movement of said chuck assembly for releasing the mandrel from its upper position to assume its lower position.

7. A chuck assembly adapted to form a portion of a pipe elevator for engaging with and suspending a pipe having its end terminating in a screw thread comprising, in combination, an indexing ring defining a. tube of fixed diameter terminating in a shoulder and mating with the end of the thread defined by the pipe, a plurality of jaw members carried by said indexing ring and arranged for radial movement with respect thereto, with surfaces of said jaw members defining a thread adapted to engage with the pipe thread when the jaw members are in their radially extended positions.

8. A chuck assembly adapted to form a portion of a pipe elevator for engaging with and suspending a section of pipe having its end terminating in a screw thread comprising, in combination, an indexing ring defining a tube of fixed diameter terminating in a shoulder and mating with the end of the thread defined by the pipe, a plurality of jaw members carried by said indexing ring and arranged for radial movement with respect there-- to with surfaces of said jaw members defining a thread adapted to engage with said pipe when said jaw members are moved to their radially extended positions, a guide cone carried by said jaw members arranged to remain concentric with said indexing means and means carried by the jaw members adapted to bias said jaw members radially inward.

ALBERT L. STONE.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 455,037 Gardner June 30, 1891 1,083,200 Diehl Dec. 30, 1913 1,191,755 Andrews July 18, 1916 1,696,526 Crossen Dec. 25, 1928 1,752,656 Spang -1 Apr. 1, 1930 2,158,373 Long May 16, 1939 2,279,315 Hertel Apr. 14, 1942 2,290,409 Cuthill July 21, 1942 2,379,210 Alyea June 26, 1945 2,414,092 Charwinsky Jan. 14, 1947 2,496,360 Stone Feb. 7, 1950 FOREIGN. PATENTS Number Country Date 5,162 Austria of 1901 

